AB0301 AUTOIMMUNE POLYENDOCRINOPATHY SYNDROMES IN PATIENTS WITH RHEUMATOID ARTHRITIS: A SINGLE-CENTER STUDY ON 2166 PATIENTS
Authors: G. I. Gozzoli, E. Piovani, P. Bizioli, M. Taglietti, M. Fredi, C. Cappelli, F. Franceschini
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Autoimmune polyendocrinopathy syndromes (APS) include heterogeneous clinical conditions characterized by functional alterations of at least one endocrine gland associated with other autoimmune diseases. APS-1 is a rare disease due to gene AIRE mutation and characterized by at least two of the following manifestations: chronic mucocutaneous candidiasis, hypoparathyroidism and Addison's Disease (AD). APS-2 is characterized by the presence of AD associated with at least one between Diabetes Mellitus Type 1 (DM1) and autoimmune thyroid disease (Hashimoto's Thyroiditis (TH) or Graves-Basedow Disease (GD)). APS-3 includes the association of autoimmune thyroiditis and other autoimmune manifestations, excluding hypoparathyroidism and AD. APS-4 is characterized by autoimmune activity against an endocrine organ in combination with at least one more autoimmune disease not included in previous definitions. As of today, there is very little data in literature about the prevalence of APS. Scarce data are available on the association between rheumatologic diseases and endocrine disorders. <h3>Objectives</h3> This paper aims to describe the prevalence of APS in our cohort of rheumatoid arthritis (RA) patients and to assess the possible association between autoimmune endocrine diseases, RA and gender. <h3>Methods</h3> This retrospective observational study collected medical history, biochemical and immunological data and risk factors about 2166 RA patients older than 18 years of age examined by our Department of Rheumatology from January 1, 2020 to August 1, 2022. Patients included presented at least one additional non-rheumatologic organic autoimmune disease. The prevalence of autoimmune diseases in our cohort were compared with those reported in the literature. <h3>Results</h3> This study included 2166 RA patients (534 men, 1632 women, M/F ratio 1:3). We found 352 patients (16%) having at least one autoimmune disease other than RA. The cohort consisted of 307 (87%) women, 45 (13%) men, M/F ratio 1:7, with mean age 63 ± 17 years at the time of examination. Among our patients, 300 (85%) presented with one additional non-rheumatologic autoimmune disease, 43 (12%) two non-rheumatologic autoimmune diseases, and 9 (3%) three non-rheumatologic autoimmune diseases. Figure 1 shows the autoimmune disorders collected. No cases of AD, chronic mucocutaneous candidiasis, hypoparathyroidism, myasthenia and AIRE mutation were found. In our cohort, no patient satisfied diagnostic criteria for APS 1 and 2; 212 (61%) patients presented with APS-3, 7 (2%) patients had APS-4 (all with RA and DM1 association). The diagnosis of APS occurred more frequently in female than in male patients, 199/1632 (12%) vs 20/534 (4%) (p&lt; 0,001, OR 3,56, CI 2,29-5,71). Moreover differences related to gender were also evaluated for all the non-rheumatologic autoimmune disease, and a significant association between RA female patients and HT was found: 179/1632 (11%) vs 18/534 (3%) (p&lt;0,001, OR 2,30, CI 1,22-4,33). Finally, comparing the prevalence of these autoimmune diseases in our cohort with those of the general population, we found higher prevalence for HT (9% vs 5%), autoimmune urticaria (0,7% vs 0,1%), DM1 (0,5% vs 0,3%), inflammatory bowel disease (0,5 vs 0,3%), alopecia (0,5% vs 0,1%), primary biliary cirrhosis (0,1% vs 0,03%), autoimmune hepatitis (0,09% vs 0,01%), autoimmune thrombocytopenia (0,05% vs 0,01%) and pemphigoid (0,05% vs 0,025%). Concerning risk factors, 78 (22%) patients had family history of autoimmune disease, 93 (26%) smoked, 23 (7%) had BMI&gt;30. <h3>Conclusion</h3> The presence of at least one non-rheumatologic autoimmune disease was a nor rare event in our cohort of RA patients, with HT as the most frequent endocrine disease in our cohort. Among these cases, the diagnosis of APS was present in 62% of cases, mostly APS-3 and is more frequently found in female RA patients. Finally, we observed how the frequency of non-rheumatologic autoimmune diseases seems to be higher in RA patients than in general population. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.